<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>首页</title>
</head>
<body>
  <h1>首页</h1>
  <hr>
  {% if username %}
  <p>
        当前登录用户: {{username}}
      <a href="/logout">注销</a>
  </p>

  {% else %}
  <a href="/login">登录</a>

  {% endif %}

  <a href="/login">登录</a>
</body>
</html>